1. Field of the Invention
The present invention relates to a system for supplying a fixed amount of fluid, and in particular relates to a system which comprises a fluid accommodating unit formed of a fluid accommodating bag for accommodating fluid and a pump for delivering the fluid from the fluid accommodating bag and a fluid supplying device body in which the fluid accommodating unit is detachably placed and a pump driving mechanism for driving the pump is provided, wherein when supplying the fluid, a fixed amount of fluid is supplied by placing the fluid accommodating unit in the fluid supplying device body.
2. Description of the Related Art
As a system for supplying a fixed amount of fluid, there has been a post-mix-type beverage supplying system. In such a beverage supplying system, a fluid accommodating unit is detachably placed in a fluid supplying device body and has a bag in box (BIB) therein which accommodates condensed syrup such as that of coffee or tea. When supplying beverage, a fixed amount of the syrup is delivered to a cup, etc., with a pump so as to supply the beverage by mixing the syrup with water, carbonated water, or boiling water.
In such a system, a predetermined fixed amount of the syrup always requires being delivered every time of the beverage supply. Since the syrup once delivered may be contaminated by various germs when it flows into the pump or the BIB, the reverse flow of the syrup has to be securely prevented.
As one of such systems, there is provided a system using a tube pump shown in FIGS. 10A and 10B (see Japanese Unexamined Patent Application Publication No. 04-42271). In the system, a fluid accommodating unit 110 for enclosing syrup therein, which is placed in a supplying device 100, comprises a BIB 113, in which a bag 112 made from flexible film is placed in a box 111, and a tube 114 made from an elastic material such as silicone rubber and attached to the BIB 113 so as to hang therefrom.
The supplying device 100 is provided with a pump unit 120 disposed at a position where the tube 114 hangs, which forms the tube pump in cooperation with the tube 114. At a position lower than the pump unit 120 in the supplying device 100, a tube-pinching device 140 is provided for sealing up the end of the tube 114 when the syrup is not delivered. In addition, a container 145 shown in FIG. 10A is a paperboard cup, etc., for receiving beverage therein.
The pump unit 120 comprises a tube-guide member 121 with a circular tube-guide path 123 formed on one face thereof and a driving cylinder 122 for rotating the tube-guide member 121 about a rotating axis 124. The tube-guide member 121 is driven by the driving cylinder 122 so as to be switched between a pump-driving position (shown by a solid line in FIG. 10A) at which the pump fixed by a locking member of the tube-guide member 121 can be driven and a tube-inserting position (shown by a phantom line in FIG. 10A) used when the tube is inserted.
The pump unit 120 also comprises a rotating roller 130 for pinching the tube 114 against the tube-guide member 121 so as to squeeze the syrup in the tube 114 therefrom. The rotating roller 130 comprises a disc-like rotating base plate 131 driven by a driving motor 134 and rollers 132 rotatably fixed to a plurality (three in this example) of pins 133 spaced around the circumference of the rotating base plate 131 at equal intervals. The rotating roller 130 is driven by a predetermined rotating angle in accordance with the amount of the syrup required to be delivered.
When the fluid accommodating unit 110 is attached thereto, the tube-guide member 121 is switched to the tube-inserting position so that the tube 114 is arranged between the tube-guide member 121 and the rotating roller 130 and then, the tube-guide member 121 is switched to the pump-driving position.
The tube-pinching device 140 comprises a fixing member 141 fixed to the supplying device 100, a pinching member 142 for pinching an end portion of the tube 114 against the fixing member 141 so as to seal the tube 114 off, and a cylinder member 143 for pushing and retracting the pinching member 142. Therefore, various germs and the like cannot enter thereinto via the tube 114.
However, in a system for supplying a fixed amount of fluid using such a tube pump, when exchanging a BIB, troublesome processes have to be stepped, in which the tube-guide member 121 is switched to the tube-inserting position, the tube 114 is arranged between the tube-guide member 121 and the rotating roller 130 by curving the tube 114, and the tube-guide member 121 is then switched to the pump-driving position.
Although the end of the tube is sealed off by the pinching device in a state that the fluid accommodating unit 110 is placed in the supplying device, there may be a problem in which during exchanging the BIB, the syrup accommodated in the BIB is discharged from the tube or air enters into the BIB so that various germs are mixed with the syrup in the BIB, because any special closing means is not provided in the tube itself.
Accordingly, instead of the tube pump of a conventional system for supplying a fixed amount of fluid, the use of a bellows pump is expected. The bellows pump comprises a bellows having an internal volume being variable by the external drive and two check valves respectively arranged in the flow-inlet and the flow-outlet of the bellows.
The check valve for use in a conventional bellows pump generally has a structure in which a fluid path formed on a valve base is opened and closed by a planer or spherical valve body.
That is, in the check valve using the planer valve body: one end of the planer valve body is attached to the valve base; the opening of the fluid path is normally closed due to the elasticity of the valve body; when fluid flows toward the delivery, the valve body is separated from the opening of the fluid path due to the pressure of the fluid so that the opening of the fluid path is opened.
In the check valve using the spherical valve body: the valve body is pushed to the opening of the fluid path from the downstream by an elastic member such as a coil spring so that the opening of the fluid path is normally closed; when fluid flows toward the delivery, the valve body is separated from the opening of the fluid path by compressing the coil spring, etc., due to the pressure of the fluid so that the opening of the fluid path is opened.
However, in the above-mentioned check valves, although the reverse flow of the fluid can be prevented during driving of the pump, the check valve may be opened due to the external impulse so that there have been problems that the leakage is produced from the check valve during the fluid delivery so that the syrup may be delivered in excess of a predetermined amount or the syrup once delivered flows backward into the pump so that the syrup in the pump and the BIB may be contaminated with various germs.
In view of the above-described situations, the present invention has been made, so that it is an object of the present invention to provide a disposable mechanism for taking out a fixed amount of fluid and a system for supplying a fixed amount of fluid in which the reverse flow of the fluid is eliminated and a precise fixed amount of the fluid can be delivered.
According to the present invention, the above-mentioned object can be achieved by a disposable mechanism for taking out a fixed amount of Fluid and a system for supplying a fixed amount of fluid which will be described.
In accordance with a first aspect of the present invention, a disposable mechanism for taking out a fixed amount of fluid by bellows pump with check valves comprising a bellows pump, two check valves attached to both ends of the bellows pump, a bag made from flexible film positioned at the check valve of fluid-flow-inlet side and the previously-mentioned check valve is comprised of; hemisphere shaped valve base, hemisphere shaped valve of elastic material such as rubber which the periphery being attached to the hemisphere shaped valve base and are shaped to cover closely the round surface of the hemisphere shaped valve base and has round holes located near the center of it, and fluid piercing hole placed in piercing condition in the center of the valve base from the flat surface to the round surface.
In accordance with a second aspect of the present invention, a disposable mechanism for taking out a fixed amount of fluid by bellows pump with check valves, described in claim 1, characterized by fluid piercing holes placed several on circumference of check valve, and each fluid piercing hole is either placed in radial direction from the flat surface of the hemisphere shaped valve base to the round surface or in vertical direction from the flat surface of the valve base.
In accordance with a third aspect of the present invention, a system for supplying a fixed amount of fluid comprises a fluid accommodating unit comprising a fluid accommodating bag for accommodating fluid therein and a pump connected to the fluid accommodating bag for pumping the fluid, and a fluid supplying device body in which the fluid accommodating unit is detachably disposed and in which a pump driving mechanism for driving the pump is disposed, the system supplying a fixed amount of the fluid by the fluid accommodating unit in the fluid supplying device body when the fluid is being supplied, wherein the pump of the fluid accommodating unit is a bellows pump comprising a bellows and two check valves arranged in a fluid inlet and a fluid outlet of the bellows, respectively, the check valve comprising a valve base whose downstream surface is curved to be convex toward the downstream side and a valve body made from an elastic thin plate for covering the downstream surface of the valve base, the valve base having fluid-flow-through holes extending from the fluid upstream surface to portions of the downstream surface covered with the valve body, the valve body being fixed to the valve base on the periphery of the valve body while having a hole at the center thereof for allowing the flow of the fluid, and wherein the pump driving mechanism of the fluid supplying device body drives the bellows so as to expand and contract the bellows at a predetermined stroke when the fluid accommodating unit is placed in the system for supplying a fixed amount of fluid.
In accordance with a fourth aspect of the present invention, a system for supplying a fixed amount of fluid comprises a fluid accommodating unit comprising a fluid accommodating bag for accommodating fluid therein and a pump connected to the fluid accommodating bag for pumping the fluid, and a fluid supplying device body in which the fluid accommodating unit is detachably disposed and in which a pump driving mechanism for driving the pump is disposed, the system supplying a fixed amount of the fluid by the fluid accommodating unit in the fluid supplying device body when the fluid is being supplied, wherein the pump of the fluid accommodating unit is a bellows pump comprising a bellows and two check valves arranged in a fluid inlet and a fluid outlet of the bellows, respectively, the check valve comprising a valve base whose downstream surface is curved to be convex toward the downstream side and a valve body made from an elastic thin plate for covering the downstream surface of the valve base, the valve base having fluid-flow-through holes extending from the fluid upstream surface to portions of the downstream surface covered with the valve body, the valve body being fixed to the valve base on the periphery of the valve body while having a hole at the center thereof for allowing the flow of the fluid, the pump driving mechanism of the fluid supplying device body driving the bellows so as to expand and contract the bellows at a predetermined stroke when the fluid accommodating unit is placed in the system for supplying a fixed amount of fluid, and wherein an outlet of the fluid accommodating unit is provided with closing means for closing the outlet and the fluid supplying device body is provided with a sealing-valve driving device for driving the closing means when the bellows pump is not being driven.
According to the third and the fourth aspect of the present invention, because in the check valve of the bellows pump, the downstream surface of the valve base is curved to be convex toward the downstream side and the fluid-flow-through holes are formed so as to extend from the fluid upstream surface of the valve base to portions of the downstream surface covered with the valve body, and the valve body made from an elastic thin plate for covering the downstream surface of the valve base is fixed to the valve base on the periphery of the valve body while having a hole at the center thereof for allowing the flow of the fluid, when pressure is not applied to the valve body from the upstream or pressure is applied to the valve body from the downstream, the valve body adhere closely to the downstream surface of the valve base so as to plug the fluid-flow-through holes.
Accordingly, fluid is not allowed to flow toward the upstream in these states. Only when pressure is applied to the fluid from the upstream, the valve body is pushed toward the downstream so as to form a clearance between the valve body and the valve base, so that the fluid flows from the fluid-flow-through holes of the valve base toward the downstream via the hole for allowing the flow of the fluid of the valve body.
Because the pump driving mechanism of the fluid supplying device body drives the bellows so as to expand and contract the bellows at a predetermined stroke when the fluid accommodating unit is placed in the system for supplying a fixed amount of fluid, a fixed amount of the fluid is securely pumped by driving the bellows pump.
Furthermore, according to the fourth aspect, an outlet of the fluid accommodating unit is provided with closing means for closing the outlet and the fluid supplying device body is provided with a sealing-valve driving device for driving the closing means when the bellows pump is not being driven, thereby the reverse flow of the fluid from the outlet of the fluid accommodating unit is securely prevented.
In a system for supplying a fixed amount of fluid according to the third and the fourth aspect of the present invention, an end of the fluid accommodating unit is preferably provided with replacement-part-fitting means which can attach an attached replacement part to the fluid accommodating unit.
The end of the fluid accommodating unit may be provided with the replacement-part-fitting means, so that an attached replacement part having a required function may be attachable and detachable thereto freely. As the attached replacement part, a reverse-flow-preventing device of fluid and a mixing device with other kinds of fluid may be adopted.
Preferably, the attached replacement part is a mixing device for mixing a fixed amount of the fluid supplied with another kind of fluid. As the other kinds of fluid, there are cold water, carbonated water, warm water, and so forth, and the most suitable mixing device for the kind of the fluid may be selected therefrom for attaching thereto.
Thereby, when a supplying system for one kind of beverage is changed to that for another different kind of beverage, the entire fluid supplying system is not necessarily required to change only when the attached replacement part is replaced.
Preferably, the valve body is a thin film having a predetermined thickness. The valve body is thereby manufactured easily by punching the thin film with a predetermined thickness so as to have a predetermined shape.
Preferably, the valve body is a thin film in which the thickness decreases toward the hole formed at the center.
Because the valve body is a thin film with the thickness decreasing toward a hole formed at the center thereof, so that it is elastically deformed by a small force, a small pressure difference between the upstream and the downstream of the valve causes the valve body to stick to or separate from the valve base, resulting in the achievement of the secure opening and closing operations of the valve.
Preferably, the pump driving mechanism is a reciprocating mechanism for vertically reciprocating at least one of upper and lower ends of the bellows.
In this case, at least one of upper and lower ends of the bellows is vertically reciprocated by the pump driving mechanism so that fluid can be fed under pressure in a one-way direction by the operation of the two check valves respectively arranged in the fluid-flow-inlet in the upstream of the bellows and the fluid-flow-outlet in the downstream of the bellows. It is sufficient for the vertical reciprocating only to change the internal volume of the bellows, so that one or both of the upper and lower ends may be vertically moved.
Preferably, the pump driving mechanism is provided with control means for controlling the number of cycles of the reciprocating driving and the reciprocating speed during one time supplying operation.
The number of cycles of the reciprocating driving and the reciprocating speed of the bellows during one time supplying operation are thereby controlled by the control means in the pump driving mechanism, so that the fluid may be pumped at a amount and speed optimum for the kind and viscosity, etc. of the fluid.
Preferably, the fluid accommodating unit is provided with a sealing-valve mechanism as closing means and the fluid supplying device body is provided with a driving mechanism for driving the sealing-valve mechanism.
When the fluid accommodating unit is provided with the sealing-valve mechanism which is driven by the driving mechanism for driving the sealing-valve mechanism disposed in the fluid supplying device body, the sealing-valve mechanism contacting the fluid can be replaced together with the fluid accommodating unit during the replacement of the fluid accommodating unit, thereby not only saving a time and energy for the replacement but also the leakage of the fluid out of the unit during the replacement can be prevented so as to eliminate labor for cleaning the fluid accommodating unit.
Preferably, the sealing-valve mechanism of the fluid accommodating unit is formed as a cylinder which vertically moves so that the periphery of the valve body hole of the lower check valve can be pushed against the valve base while allowing the fluid to flow-through the inside of the cylinder.
In this case, because the sealing-valve mechanism of the fluid accommodating unit is formed as the cylinder which vertically moves so that the periphery of the valve body hole of the lower check valve can be pushed against the valve base while allowing the fluid to flow-through the inside of the cylinder, the number of parts of the sealing-valve mechanism can be reduced, resulting in reduction of the manufacturing cost.